5. Boys San (Inter Milan)

F.C. Internazionale, or Inter Milan, is supported by a quarter of Italian football fans. Historically, Inter fans came from the middle-class and the Boys San is one of the oldest groups of hardcore fans in European football; they were founded in 1969, and are generally considered politically right wing.

As stated earlier, Inter and A.C. Milan share San Siro stadium, and the resulting derby between the two Milan teams has always been competitive and ferocious. For their part, Boys San designed a logo featuring the Italian flag and a hand holding a knife. Seated in the Curva Nord section of the stadium, they wave flags, chant in driving unison and light choreographed flares in the Italian colors — and it’s not unheard of for Boys San to throw their flares onto the field if they dislike the ref's call.